Answer:
Avogadro's number is 6.022×1023 molecules. With Avogadro's number, scientists can discuss and compare very large numbers, which is useful because substances in everyday quantities contain very large numbers of atoms and molecules.
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Answer:
Explanation:
We are asked to find how many kilojoules of energy would be required to heat a block of aluminum.
We will use the following formula to calculate heat energy.
The mass (m) of the aluminum block is 225 grams and the specific heat (c) is 0.897 Joules per gram degree Celsius. The change in temperature (ΔT) is the difference between the final temperature and the initial temperature.
- ΔT = final temperature - inital temperature
The aluminum block was heated from 23.0 °C to 73.5 °C.
- ΔT= 73.5 °C - 23.0 °C = 50.5 °C
Now we know all three variables and can substitute them into the formula.
- m= 225 g
- c= 0.897 J/g° C
- ΔT= 50.5 °C
Multiply the first two numbers. The units of grams cancel.
Multiply again. This time, the units of degrees Celsius cancel.
The answer asks for the energy in kilojoules, so we must convert our answer. Remember that 1 kilojoule contains 1000 joules.
Multiply by the answer we found in Joules.
The original values of mass, temperature, and specific heat all have 3 significant figures, so our answer must have the same. For the number we found, that is the tneths place. The 9 in the hundredth place tells us to round the 1 up to a 2.
Approximately <u>10.2 kilojoules</u> of energy would be required.
Grady is doing an experiment about the solubility of sugar. He puts 100 milliliters of water in each of three beakers. He leaves the first beaker at room temperature, heats the second beaker to 60°C, and heats the third beaker until the water boils at 100°C. The variable Grady change on purpose in the experiment is the temperature of water in each beaker .
Variables in the experiment is the any factor that can exist in different types or amount. There are three types of variables: independent variable , dependent variable , controlled variable. The independent variable is the variable you changed in the experiment. dependent variable is that changes because of independent variable. the controlled variable is the constant one.
Thus, Grady is doing an experiment about the solubility of sugar. He puts 100 milliliters of water in each of three beakers. He leaves the first beaker at room temperature, heats the second beaker to 60°C, and heats the third beaker until the water boils at 100°C. The variable Grady change on purpose in the experiment is the temperature of water in each beaker .
To learn more about variables here
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Explanation:
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-renewable
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Answer:
Zn + 2HCl → ZnCl2 + H2
Explanation:
Zn + HCl → ZnCl2 +
The complete equation is given below:
Zn+ HCl → ZnCl2 + H2
Now we can balance the equation by doing the following:
There are 2 atoms of Cl and 2 atoms of H on the left. This can be balanced by putting 2 in front of HCl as shown below:
Zn + 2HCl → ZnCl2 + H2
